Iron and 1,3,5-benzenetricarboxylic (Fe–BTC) metal–organic coordination polymers are synthesized via a simple solvothermal method. The as-synthesized Fe–BTC polymers exhibit gel behavior, which is stable in common organic solvents or in water. The Fe–BTC polymer as an adsorbent for arsenic removal from water is tested. The kinetics and thermodynamics of arsenic adsorption by the Fe–BTC polymer in aqueous solution are investigated comprehensively. The effect of pH on the adsorption is also investigated. Kinetic studies show that the kinetic data are well described by the pseudo-second-order kinetic model. The thermodynamic analysis indicates that the adsorption is spontaneous. The adsorption isotherms can be well described with the Langmuir equation. The Fe–BTC polymers show relatively high arsenic adsorption capacity, more than 6 times that of iron oxide nanoparticles with a size of 50 nm and 36 times that of commercial iron oxide powders. Hence, the as-synthesized Fe–BTC polymers possess relatively high ...

Iron and 1,3,5-Benzenetricarboxylic Metal–Organic Coordination Polymers Prepared by Solvothermal Method and Their Application in Efficient As(V) Removal from Aqueous Solutions

Facile synthesis of MIL-100(Fe) under HF-free conditions and its application in the acetalization of aldehydes with diols

A MIL-53(Fe) analogue was successfully synthesized by a HF free-solvothermal method. The sample was characterized by XRD, N2 adsorption (BET), TEM, FTIR, XPS and AAS. From the N2 adsorption–desorption isotherms, it can be seen that the structure of MIL-53(Fe) in the anhydrous form exhibits closed pores with almost no accessible porosity to nitrogen gas. The XPS results reveal that Fe is really incorporated into the MIL-53(Fe) framework. In the hydrated form, the pores of MIL-53(Fe) are filled with water molecules. Thus, MIL-53(Fe) exhibited a very high adsorption capacity of As(V) in aqueous solution (Qmax of 21.27 mg g−1). Adsorption kinetics data revealed that As(V) adsorption isotherms fit the Langmuir model and obey the pseudo-second-order kinetic equation.

Arsenic removal from aqueous solutions by adsorption using novel MIL-53(Fe) as a highly efficient adsorbent

Magnetic responsive metal-organic frameworks nanosphere with core-shell structure for highly efficient removal of methylene blue

Electrochemical nitrogen reduction reaction (NRR) over nonprecious-metal and single-atom catalysts has received increasing attention as a sustainable strategy to synthesize ammonia. However, the atomic-scale regulation of such active sites for NRR catalysis remains challenging because of the large distance between them, which significantly weakens their cooperation. Herein, the utilization of regular surface cavities with unique microenvironment on graphitic carbon nitride as "subnano reactors" to precisely confine multiple Fe and Cu atoms for NRR electrocatalysis is reported. The synergy of Fe and Cu atoms in such confined subnano space provides significantly enhanced NRR performance, with nearly doubles ammonia yield and 54%-increased Faradic efficiency up to 34%, comparing with the single-metal counterparts. First principle simulation reveals this synergistic effect originates from the unique Fe-Cu coordination, which effectively modifies the N2 absorption, improves electron transfer, and offers extra redox couples for NRR. This work thus provides new strategies of manipulating catalysts active centers at the sub-nanometer scale.

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S. Srivastava

Papers

X-ray photoelectron spectra of metal complexes of substituted 2,4-pentanediones